Photolysis of phenyl azide

The quantum yield for the photodissociation of phenyl azide in the concentration range from 10^–4 to 10^–1 M is 0.4–0.5, while the yield of azobenzene does not exceed 50%.Institute of Chemical Physics, Russian Academy of Sciences 142432 Chernogolovka. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 752–754, March, 1992.     

Reaction of dihydropyran with phenyl azide

The reaction of dihydropyran with phenyl azide leads to the formation of N-phenyliminotetrahydropyran.     

The question of hydrogen and randomization in phenyl isocyanide

The loss of HCN and DCN from 2,4,6-d₃-phenyl isocyanide is preceded by H/D randomization in the large majority of k-states which could be sampled in this study.     

The temperature dependent photochemistry of phenyl azide in diethylamine

The photochemistry of phenylazide in diethylamine changes from products consistent with electrophilic singlet intermediates to products consistent with triplet nitrenes as the temperature is lowered from 273 to 77k.     

Reaction of phenyl azide with N,N-dimethyl-aminomethylenephenylphosphines

Phenyl azide reacts with N,N-dimethylamino-P-phenylmethylenephosphines with cleavage of the phosphoruscarbon double bond and formation of the dimer of diiminophosphorane and amidines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2381–2382, October, 1989.     

RNA-tethered phenyl azide photocrosslinking via a short-lived indiscriminant electrophile

Arylazide mediated photocrosslinking has been widely used to obtain structural constraints in biological systems, even though the reactive species generated upon photolysis in aqueous solution have not been well characterized. We establish a mechanistic framework for formation of adducts between photoactivated 3-hydroxyphenyl azide and RNA. Tethered to an internal site in an RNA duplex via a 2'-amido linkage, photolysis of the aryl azide yields a cross-strand cross-link. Analysis of the ability of reagents with diagnostic reactivities to intercept formation of this cross-strand cross-link supports the assignment that the photoactivated intermediate is the ketenimine or a ketenimine-derived ring expansion product. Neither the initially produced singlet nitrene nor the subsequently formed triplet nitrene contribute to cross-link formation. Argon matrix and time-resolved solution experiments show that photolysis of free 3-hydroxyphenyl azide releases (in 相似文献   

Diphthalolylpyrkolidines from 2-arylidene-1,3-indandiones and phenyl azide

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 269–270, February, 1989.     

1,3-Dipolar cycloaddition between substituted phenyl azide and 2,3-dihydrofuran

A theoretical study was performed on the 1,3-dipolar cycloaddition between 2,3-dihydrofuran and substituted phenyl azide using Density Functional Theory (DFT) in combination with a 6-311++G(d,p) basis set. The optimum geometries for reactant, transition state and product, as well as the kinetic data, rate constants and reaction constant (ρ) were investigated to rationalise the substitution effects and reaction rates of the 1,3-dipolar cycloaddition process in various solvents. The DFT calculation and Frontier Molecular Orbital (FMO) theory as well as the atomic Fukui indices show that the electron-withdrawing substituents enhance the reaction constant (ρ > 0), especially in polar aprotic solvents. Consequently, small changes in the rate constant of the reaction in various solvents and geometric similarity between reactants and transition state structures were suggested as the early transition state mechanism for electron-withdrawing substituents. In addition, the slope of the Hammett plot and susceptibility of the reaction to electron-withdrawing substituents in various solvents confirmed the mechanism.     

The reactions of 2H-1,2,3-diazaarsoles with phenyl azide

2-Phenyl-5-methyl- and 2,5-diphenyl-2H-1,2,3-diazaarsoles 1a,b react with phenyl azide to give several crystalline products: tricyclic derivatives 2a,b and 4,4′-bis(2H-1,2,3-diazaarsoles) 5a,b formed at room temperature, and a cycloadduct 6a obtained at +4°C. Compound 6a undergoes a fast rearrangement in solutions of Et₃N or pyridine to give a stable dicoordinate arsenic compound, the 2H-1,2,3-diazaarsole 7a. Heating solutions of 2a under reflux in an inert atmosphere leads to 5a and of 2b, in the presence of water, to 4b. The structures of 2a, 4b, and 7a were characterized by X-ray crystal structure determinations. © 1996 John Wiley & Sons, Inc.     

3-nitro- and 3-bromo-3-nitroacrylates in reactions with phenyl azide

1,3-Dipolar cycloaddition of alkyl 3-nitro-and 3-bromo-3-nitroacrylates to phenyl azide gives regioisomeric alkyl 5(4)-nitro-1-phenyl-4,5-dihydro-1H-1,2,3-triazole-4(5)-carboxylates, the corresponding triazoles both with and without nitro group, and alkyl 3-nitro-1-phenylaziridine-2-carboxylates. Nitrotriazolecarboxylates were found to lose the ester moiety during chromatographic separation of the products on aluminum oxide. The structure of the products was determined on the basis of IR, ¹H NMR, and X-ray diffraction data.     

Transient absorption spectral evidence for phenyl nitrene as the chain propagator in the photo-initiated autocatalytic chain decomposition of phenyl azide and phenyl isocyanate

Transient absorption spectra were recorded 15 ns to 6 μs following a 266 nm laser pulse for phenyl azide and for phenyl isocyanate in aerated acetonitrile and 3-methylpentane solutions. Transient spectra which are independent of concentration and of delay time, are essentially identical for phenyl azide and for phenyl isocyanate, except at higher energies where phenyl azide absorbs, and are assigned as that of triplet phenyl nitrene. Since there is no spectral evidence for a second species, phenyl nitrene is thought the chain propagator in the autocatalytic chain decomposition that occurs for phenyl azide and for phenyl isocyanate.     

Allenyl azide cycloaddition chemistry. Synthesis of annelated indoles from 2-(allenyl)phenyl azide substrates

[reaction: see text] Thermolysis of 2-(allenyl)phenyl azides leads to a cascade cyclization sequence furnishing both C(2)-C(3) and N-C(2) cyclopentannelated indoles.     

An ultrafast study of phenyl azide: the direct observation of phenylnitrenium ion

Ultrafast photolysis (lambda(ex) = 308 nm) of phenyl azide in 100% formic acid produces a broadly absorbing transient within the instrument time resolution (300 fs), which is assigned to an excited state of the azide. The azide excited state fragments within 300 fs to form singlet phenylnitrene. The decay of the nitrene (tau = 12.0 ps) produces a new species with absorption centered at 500 nm, which is assigned to phenylnitrenium ion. The lifetime of phenylnitrenium ion is 110 ps in 100% formic acid. This is the first spectroscopic observation of phenylnitrenium ion.     

1-Bromo-3,3,3-trifluoro-1-nitropropene: Synthesis and reaction with phenyl azide

An improved procedure was developed for the synthesis of 3,3,3-trifluoro-1-nitropropene, and a new representative of gem-bromonitroalkenes, 1-bromo-3,3,3-trifluoro-1-nitropropene, was synthesized therefrom. Its reaction with phenyl azide gave a mixture of two regioisomeric 1,2,3-triazoles, from which pure 5-nitro-1-phenyl-4-(trifluoromethyl)-1H-1,2,3-triazole was isolated.     

Reaction of 2-phenyl(acetyl)-5-methyldiazaphosphole with phenyl azide

Conclusions The reaction of 2-phenyl(acetyl)-5-methyldiazaphospholes with phenyl azide results in the formation of trimers which form 2-phenyl(acetyl)-3-oxo-3-anilino-5-methyl-1,2,3-diazaphospholines during hydrolysis.Translated from Izvestiiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1600–1602, July, 1981.     

Semiempirical description of the C6H5N reactive intermediate in phenyl azide photolysis

The C₆H₅N intermediate generated by photolysis of phenyl azide in solution is studied by semiempirical computations separately parametrized for thermochemistry and spectra. We find that the intermediate which absorbs only weakly in the region 320–370 nm and which is trapped by amines is the bicyclic azirine singlet, as proposed by DeGraff, Gillespie and Sundberg. Other species such as azepinylidine, the distorted azallyl azacycloheptatetraene and pyridyl carbene seem less likely candidates, either because they would be expected to have a rich spectrum in the visible or because they are unstable relative to the azirine. The adduct formed during trapping by amines rearranges by a suprafacial [1, 3] sigmatropic shift, in contradiction to Woodward-Hoffman predictions. Details of the path are easily rationalized as due to specific orbital interactions.     

Electron-impact studies—LI: Hydrogen randomization in the stilbene molecular ion

Hydrozen randomization precedes the formation of M^+· ? H· and M^+· ? CH₃· species from the stilbene molecular ion at 15 eV. The carbon atom involved in the M^+· ? CH₃· elimination originates randomly from the whole molecule. The [M ? 15] ion (m/e 165) in the spectra of stilbene and 9,10-dihydrophenanthrene is produced from a common ion.     

The catalytic carbonylation at atmospheric pressure of phenyl azide to PhNCO,PhNHCONHPh and PhNHCOOEt

The catalytic activities of rhodium(I) complexes in the carbonylation of phenyl azide at atmosphere pressure, leading to the corresponding isocyanate have been studied. [Rd(DPE)₂] Cl and RhCl(CO)(PPh₃)₂ are the most active catalysts, and maintain their high activity even in the presence of aniline (which gives diphenylurea) or ethanol (which gives carbamate).